While the wording of SOPA hasn't changed over the last four weeks, the politics have. A person familiar with the situation told CNET that BSA's volte-face came after Microsoft and, to a lesser extent, other members of the trade association had reviewed the bill and informed Holleyman of their displeasure.

It's possible that Microsoft is reluctant to oppose SOPA publicly because it would jeopardize its relationship with Smith, the influential chairman of the House Judiciary committee, which oversees copyright law. Microsoft declined to respond to a query from early yesterday, with a representative saying only that we are "unable to accommodate your request."

SOPA, along with the PROTECT IP act in the Senate, give content-producing companies the right to order a take down for a website that they believe is infringing on a copyright. If you even host links to content that infringes on a copyright, you have to take it down.

If not, the copyright owner can request that the infringing site has its advertising and transaction revenue cut off. Or it can request that a domain name — like businessinsider.com — be blacklisted and rendered inaccessible.